Safety critical systems are systems whose failures or malfunctions may result in significantly detrimental consequences such as death or injury to persons, severe damage or loss to equipment or to environment. Because safety critical systems have potentially dangerous consequences, the entire system undergoes a verification and validation processes to provide a certain level of confidence that the entire system operates properly and will continue to operate properly for all approved-for-use conditions.
Medical systems are an example of safety critical systems that require a certain level of confidence that the system will operate and continue to operate properly. Medical systems may detrimentally affect a user's health and well-being if not operating properly or not known to be operating properly. This is especially true for medical systems that provide user's with health-related diagnostic or therapeutic information. For example, analyte monitoring devices, such as glucose meters, provide users with diagnostic information about their blood-sugar levels. Inaccuracies or significant delays in reporting such diagnostic information may potentially lead to injury or death of a user. Furthermore, as another example, medical systems may provide users with therapeutic information such as recommended medication dosages. For instance, glucose meters may provide users with recommended insulin dosages in response to a glucose measurement in order to remedy the current or anticipated blood sugar levels. Inaccuracies or significant delays in reporting such therapeutic information may potentially lead to injury or death of the user.
Once the entire safety critical system have been verified and validated, the entire system is released and is not expected to undergo software and/or hardware changes. This provides for a very controlled system environment. New software and/or hardware changes are not introduced into the market unless and until the new hardware and/or software have undergone a new validation process. Such a controlled system environment provides a certain level of confidence that the system will not be altered or changed and potentially affects the proper operation of the system.
However, when a safety critical application (SCA) is installed on an uncontrolled data processing device (UDPD) that permits hardware and/or software changes by the user, any changes to the UDPD may detrimentally affect the proper operation of the SCA on the UDPD. UDPDs generally permit the user to make software and/or hardware changes to the device—e.g., installing/removing software programs, installing/removing drivers, adding/removing hardware components, etc. Example UDPDs may include, personal computers (e.g., desktop, notebook, etc.), mobile phones (e.g., iPhones®, Blackberry®, etc.), personal digital assistants (PDAs), etc. Thus, the uncontrolled nature of the data processing devices compromises any assurance that the SCA will operate, or continue to operate, properly on the UDPD.